FIG. 13 is a diagram showing a schematic configuration of a conventional infusion set 100. The infusion set 100 includes a flow channel 110 through which a medical solution flows. The flow channel 110 is constituted by tubes 110a and 110b. A spike 111 is provided at an upstream end of the flow channel 110, and a male connector 112 is provided at a downstream end of the flow channel 110. The tube 110a and the tube 110b are in communication with each other via a drip chamber 113. A roller clip 114 and a pinch clamp 115 are provided along the tube 110b. 
The spike 111 is inserted into a port of a medical solution bag in which a medical solution is stored. A downstream end of the male connector 112 is connected to an upstream end of a tube having a needle that is pierced into the vein of a patient. The drip chamber 113 allows visual observation of the medical solution flowing through the flow channel 110. The roller clip 114 allows the flow rate of the medical solution to be set as desired through adjustment of the cross sectional area of the medical solution flow channel of the tube 110b. The pinch clamp 115 has a function of opening and closing the medical solution flow channel of the tube 110b. 
Administration of a medical solution using the infusion set 100 having the above-described configuration is performed in the following manner.
The male connector 112 is connected to the other end of a tube having a needle provided at one end thereof, the needle being provided to be inserted into a patient. Next, the spike 111 is connected to a medical solution bag in which a medical solution is stored, with the pinch clamp 115 being closed. Next, the pinch clamp 115 is opened so as to fill the flow channel extending from the spike 111 to the needle with the medical solution. This process is generally called “priming”. Next, the pinch clamp 115 is closed. Next, the needle is inserted into the vein of a patient. After that, the pinch clamp 115 is opened so as to administer the medical solution to the patient. The flow rate of the medical solution is adjusted by using the roller clip 114. Finally, the pinch clamp 115 is closed so as to stop the administration of the medical solution.